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v3.19.1

Organization and Summary of Significant Accounting Policies (Organization and Revenue Recognition) (Details) $ in Thousands |  |  | 12 Months Ended |
--- | --- | --- | --- | ---
Aug. 22, 2018 USD ($) NotesSeries | Aug. 04, 2017 USD ($) item | Dec. 31, 2018 USD ($) | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($) | Jan. 01, 2018 USD ($)
Organizations [Line Items] |  |  |  |  |  |
Total |  |  | $ 1,358,430 | $ 1,103,743 |  |
Number of business days to pay interest |  | 5 days |  |  |  |
Maturity term |  | 10 years |  |  |  |
Maintenance Reserves |  |  | 94,522 | 75,889 |  |
Security Deposit Liability |  |  | $ 28,047 | 25,302 |  |
Revenue Recognition |  |  |  |  |  |
Minimum number of days for which lease rent and maintenance reserve payments are past due |  |  | 30 days |  |  |
Lease rent receivables past due |  |  | $ 4,800 |  |  |
Maintenance reserve receivables past due |  |  | 5,600 |  |  |
Unbilled revenue associated with outstanding contracts |  |  | 600 |  |  |
Revenue |  |  | 87,009 | 80,189 | $ 57,091 |
Other |  |  |  |  |  |
Revenue Recognition |  |  |  |  |  |
Revenue |  |  |  | 1,300 |  |
Other Assets |  |  |  |  |  |
Revenue Recognition |  |  |  |  |  |
Unbilled revenue associated with outstanding contracts |  |  |  |  |  | $ 400
Credit facility at a floating rate of interest of LIBOR plus 2.75%, secured by engines |  |  |  |  |  |
Organizations [Line Items] |  |  |  |  |  |
Total |  |  | 491,000 |  |  |
WEST III Series A 2017 term notes payable at a fixed rate of interest of 4.69%, maturing in August 2042, secured by engines |  |  |  |  |  |
Organizations [Line Items] |  |  |  |  |  |
Total |  |  | $ 274,205 | 289,295 |  |
Fixed rate (as a percent) |  |  | 4.69% |  |  |
WEST III Series B 2017 term notes payable at a fixed rate of interest of 6.36%, maturing in August 2042, secured by engines |  |  |  |  |  |
Organizations [Line Items] |  |  |  |  |  |
Total |  |  | $ 39,212 | $ 41,370 |  |
Fixed rate (as a percent) |  |  | 6.36% |  |  |
WEST IV |  |  |  |  |  |
Organizations [Line Items] |  |  |  |  |  |
Number of series notes | NotesSeries | 2 |  |  |  |  |
Aggregate principal amount | $ 373,400 |  |  |  |  |
WEST IV Series A 2018 term notes payable at a fixed rate of interest of 4.75%, maturing in September 2043, secured by engines |  |  |  |  |  |
Organizations [Line Items] |  |  |  |  |  |
Aggregate principal amount | $ 326,800 |  |  |  |  |
Total |  |  | $ 323,075 |  |  |
Fixed rate (as a percent) |  |  | 4.75% |  |  |
Notes issues at price of par (as percentage) | 99.99853% |  |  |  |  |
Maturity term | 8 years |  |  |  |  |
WEST IV Series B 2018 term notes payable at a fixed rate of interest of 5.44%, maturing in September 2043, secured by engines |  |  |  |  |  |
Organizations [Line Items] |  |  |  |  |  |
Aggregate principal amount | $ 46,700 |  |  |  |  |
Total |  |  | $ 46,154 |  |  |
Fixed rate (as a percent) |  |  | 5.44% |  |  |
Notes issues at price of par (as percentage) | 99.99504% |  |  |  |  |
Maturity term | 8 years |  |  |  |  |
WEST III |  |  |  |  |  |
Organizations [Line Items] |  |  |  |  |  |
Number of series notes | item |  | 2 |  |  |  |
WEST III | WEST III Series A 2017 term notes payable at a fixed rate of interest of 4.69%, maturing in August 2042, secured by engines |  |  |  |  |  |
Organizations [Line Items] |  |  |  |  |  |
Aggregate principal amount |  | $ 293,700 |  |  |  |
Fixed rate (as a percent) |  |  | 4.69% |  |  |
WEST III | WEST III Series B 2017 term notes payable at a fixed rate of interest of 6.36%, maturing in August 2042, secured by engines |  |  |  |  |  |
Organizations [Line Items] |  |  |  |  |  |
Aggregate principal amount |  | $ 42,000 |  |  |  |
Fixed rate (as a percent) |  |  | 6.36% |  |  |
WOLF A340 LLC |  |  |  |  |  |
Organizations [Line Items] |  |  |  |  |  |
Previously held interest (as a percent) |  |  | 50.00% |  |  |
Acquisition of the remaining outstanding shares (as a percent) |  |  | 100.00% |  |  |

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